If we transform this equation from general (implicit) form
to slope form (explicit) we get y=(-1/3)x-8 .
We see that slope (coefficient of the direction) is -1/3.
The line which is perpendicular to giving line have slope which is worth 3.
Slope equation of the new line is y=3x-8 or general form (implicit)
3x-y-8=0
Good luck!!!